Radio beacon



July 9, 1940.

H. NASS RADI Q BERGEN Filed Nov. 4., 1938 ATTORNEY I Patented July 9, 1940 UNITED STATES PATENT OFFICE RADIO BEACON Heinrich Nass, Berlin, Germany, assignor to C. Lorenz Aktiengesellschaft, Berlin-Tempelhof, Germany, a company Application November 4, 1938, Serial No. 238,829 In Germany November 4, 1937 7 Claims. (Cl. 250-11) I" nate are keyed in a manner to render them al- The transmitting antenna continually fed from ternately effective and ineffective. These rea high frequency generator over a choke coil l is flectors are keyed either electrically, this. is, denoted by A While the alternately keyed reflecwith the aid of relays, or by mechanical engagetors, arranged on opposite sides of antenna A, are ment effected with the aid of switching shafts. design d R These reflectors are keyed 1 A known antenna structure of this kind onn with the aid of condensers 2, 3 located within prises two reflecting antennae, located on oppo- Screening bOXeS These Condensers are site or nearly opposite sides of the continuously ne in pa w tuning Coils T likewise fed transmitting dipole, and a switching shaft disposed in the hOXeS he keying is by this mounted transversely of the antennae and means effected y a e y detuning the 15 adapted to influence the reflecting antenna,e flector circuits in inductive and capacitive The requisite switching operations are effected fashioneither with the aid of contact or by means of In accordance with the invention the reflectors condensers. The keying shaft arranged trans- R2 are keyed by means of S s 9 versely of the antennae entails disadvantages of posed in tubular members H 0f e reflectors 20 electrical and also of mechanical nature, and In the case here Shown the Shafts 9 which are experienced if it is desired to rotate the are rotated y Sy us e s M Which antenna system. are connected with these shafts by clutches (2,

In order to do away with these disadvantages The arrangement may however be Such that it has been proposed not to arrange the keying one motor is arranged to drive both shafts as 25 shaft transversely of the antennae but to assc- Shown in g- The supporting structure of the ciate with each reflector a separate shaft 10- antenna System is Shown in dotted linescated in the direction thereof. Such two shafts The reflectors are $0 keyed that one of them is are either mechanically interconnected underihefiective Whilst the other efiective- Thereneath the antenna system or are each connected fore the rotor of one of the Condensers 2, 3 30 with a separate ynchronou t This must be so positioned as to cooperate with the rangement h e i tiu disadvantageous stator thereof whenever the rotor of the other a mu h as th switching haft disposed beside condenser is out of cooperation with its stator. the reflectors likewise entail drawbacks of both To Such end the vanes of one rotor are o s eelectric and mechanical nature, no simplification Pordmgly with {espect to those of the other rotor 35 of the antenna structure being obtained in this m the manner luustrated in Figs- 2 and In Way order to achieve this to perfection the stator of In accordance with the invention the keying each condenser can be turned in relation to the device is such that the shafts for actuating the P P thereof h then be fi in the desired P keying means are located within the reflectors, Smon- In F1115 Way It W111 be y to Provide 40 these comprising tubular members as a casing for Preclsely Complementary slghal keying, therefor. In this way an antenna structure is that keying in which two kinds of Signals obtained which has been found to be rid of any are brought to comhlete each other in a manner electric or mechanic disadvantages and is adapted to produce an .unmterrupteci usually especially for use in connection with rotatable spoken of as contmuous. dash Thus wh 45 antenna Structures ever through external influences the conditions The invention will be understood from the folggfi gg the condensers Wm be easy to lowing desfiription refe rence had to the In the case of two synchronous motors Ml, M2 aCwFnPaRYm? draw1 ng m whlfzh shows employed for driving the shafts 8, 9 these motors partially sectioned diagrammatic elevation of one 50 In radio beacons of the kind adapted alternately to produce two differently directed antenna fields, antenna systems are employed in which a transmitting dipole is constantly fed from a high frequency generator while reflecting antenembodiment thereof, Fig. 2 illustrates the arrangement of the stator and rotor condenser plates for achieving the results in accordance with this invention, Fig. 2A illustrates an arrangement of stator and rotor plates in accordance witha further feature of my invention, and Fig. 3 illustrates an arrangement for providing a common driving means for the condenser plates in each reflector antenna.

may happen to start at different times. The synchronism of the two motors, it is true, will not be impaired thereby, but an angular difference between the rotors of the condenser will be produced, a complementary keying thus not being 7 possible.

This angular difierence depends upon the number of poles of the motors, amounting to 90 degrees. in the case of four-polar motors.

Therefore a further feature of the invention conopposite sides of this main antenna, tubular antenna members forming part of the reflecting antennae, keying means at each of. the reflecting antennae for rendering said reflecting antennae effective and inefiective, and means which serves to alternately operate said keying means comprising rotatable shafts extending through said tubular antenna members for operatingsaid keying means and driving means for rotating these shafts.

2. An arrangement according to claim 1,

' wherein said driving means comprises motors each of which is coupled to one of the shafts.

3. An arrangement according to claim 1,

wherein said driving means comprises a motor common to all of the shafts.

4. An arrangement as defined in claim 1, wherein the keying means. comprises rotatable plate condensers.

5. An arrangement as defined in claim 1, wherein the keying means comprises condensers having a rotor and a stator adapted to be ad.- justed in position with respect to this rotor.

6. An arrangement according to claim 1,

, wherein the keying means comprises condensers having a rotor and a stator, such rotor comprising main vanes and auxiliary vanes, offset with respect to the main vanes by an angle adapted to compensate angular differences of the main vanes of each rotor in relation to those of the other rotor or rotors.

'7. A radio directional transmitter comprising a continually fed radiating antenna, a tubular refiecting antenna disposed on either side and in line with the said radiating antenna, a rotatable circuit element in each of said reflecting antennae for alternately rendering the said antemiae effective and inefiective, a rotatable shaft mechanically coupled with each of the said circuit elements and disposed in the center of the said tubu-= lar reflecting antennae, and driving means coupled to each of the said shafts for rotating the said circuit elements.

HEINRICH NASS. 

